As vaccines start to roll out on a large scale in Ontario, health experts are concerned some people are developing preferences about which shot in the arm they want.

A shipment of 500,000 doses is set to arrive in Canada on Wednesday, the chief executive of local partner Verity Pharmaceuticals confirmed Friday.

Health Canada says there is no evidence that the new, possibly more contagious strain found in Ontario and B.C. will cause more severe disease or impact vaccine effectiveness.